DESCRIPTION (adapted from the Abstract): Kaposi's sarcoma (KS) is a soft tissue tumor most commonly found in individuals with immunodeficiency, including the acquired immunodeficiency syndrome (AIDS). Recent studies have identified a new human herpesvirus, Kaposi's sarcoma-associated herpesvirus (KSHV)--or human herpesvirus-8 (HHV-8)--found in almost all KS tissues and body cavity-based lymphomas. This virus may play an important role in the transformation and development of KS. One of the many pertinent questions regarding this virus is its route of transmission. The Principal Investigator and his associates have initiated a collaboration with the University of Zambia Medical School to study the etiology of KS. Zambia has a very high incidence of HIV infection in women and children; moreover, KS constitutes about 20-25 of the malignancies seen in Zambian infants and children. These rates provide a unique opportunity to explore the possible vertical transmission route of HHV-8 and whether HHV-8 infection leads to KS development in children. The researchers have already found that Zambian children and infants with KS carry HHV-8 sequences and that many normal and HIV1-infected pregnant Zambian women are also infected by HHV-8. The Investigator proposes to expand on these initial observations to a large group of Zambian pregnant women to determine whether vertical transmission of HHV-8 occurs. He hypothesizes that HHV-8 can be transmitted vertically and that immune suppression, HIV-1, and other opportunistic infections increase the probability of transmission. His immediate experimental approach is to use serological tests, solution-based PCR, and in situ PCR to determine whether vertical transmission can occur, the cell types that harbor the virus, whether immune suppression, opportunistic infections, and high HHV-8 viral load correlated with vertical transmission. His long-term objective is to understand the roles played by HHV-8 in KS.